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Related papers: Structural parameters for the M31 dwarf spheroidal…

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We have used Suprime-Cam on the Subaru Telescope to conduct a V- and I-band imaging survey of fields sampling the spheroid of the Andromeda galaxy along its south-east minor axis. Our photometric data are deep enough to resolve stars down…

Astrophysics · Physics 2007-05-23 Mikito Tanaka , Masashi Chiba , Yutaka Komiyama , Masanori Iye , Puragra Guhathakurta

The dwarf galaxy distribution surrounding M31 is significantly anisotropic in nature. Of the 30 dwarf galaxies in this distribution, 15 form a disc-like structure and 23 are contained within the hemisphere facing the Milky Way. Using a…

Astrophysics of Galaxies · Physics 2020-01-15 Zhen Wan , William H. Oliver , Geraint F. Lewis , Justin I. Read , Michelle L. M. Collins

We present images for 36 galaxies of the M81 group obtained in the H-alpha line. Estimates of the H-alpha flux and star formation rate, SFR, are avialable now for all the known members of the group with absolute magnitudes down to M_B =…

Astrophysics · Physics 2008-11-26 Igor D. Karachentsev , Serafim S. Kaisin

We present results of our dynamical stream modelling for the North West Stream in the outer halo of the Andromeda galaxy (M31). Comprising two main segments, the North West Stream was thought to be a single structured arching around M31.…

Astrophysics of Galaxies · Physics 2025-06-23 Janet Preston , Denis Erkal , Michelle L. M. Collins , R. Michael Rich , Rodrigo Ibata , Maxime Delorme

Using the Advanced Camera for Surveys on the Hubble Space Telescope, we have obtained deep optical images reaching stars well below the oldest main sequence turnoff in the spheroid, tidal stream, and outer disk of the Andromeda Galaxy. We…

B and V time-series photometry of the M31 dwarf spheroidal satellite Andromeda XXI (And XXI) was obtained with the Large Binocular Cameras at the Large Binocular Telescope. We have identified 50 variables in And XXI, of which 41 are RR…

Astrophysics of Galaxies · Physics 2015-05-15 F. Cusano , A. Garofalo , G. Clementini , M. Cignoni , L. Federici , M. Marconi , I. Musella , V. Ripepi , R. Speziali , E. Sani , R. Merighi

Positional, structural and dynamical parameters for all dwarf galaxies in and around the Local Group are presented, and various aspects of our observational understanding of this volume-limited sample are discussed. Over 100 nearby galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Alan W. McConnachie

To understand the history and formation mechanisms of galaxies it is crucial to determine their current multidimensional structure. Here we focus on stellar population properties, such as metallicity and [$\alpha$/Fe] enhancement. We devise…

Astrophysics of Galaxies · Physics 2021-03-24 Grzegorz Gajda , Ortwin Gerhard , Matías Blaña , Ling Zhu , Juntai Shen , Roberto P. Saglia , Ralf Bender

We report the discovery of 59 globular clusters (GCs) and two candidate GCs in a search of the halo of M31, primarily via visual inspection of CHFT/MegaCam imagery from the Pan-Andromeda Archaeological Survey (PAndAS). The superior quality…

Using data taken as part of the Isaac Newton Telescope Wide Field Camera (INT WFC) survey of M31, we have identified an arc-like overdensity of blue, presumably metal-poor, red giant branch stars in the north-west quadrant of M31. This…

Astrophysics · Physics 2009-11-10 A. McConnachie , M. Irwin , G. Lewis , R. Ibata , S. Chapman , A. Ferguson , N. Tanvir

The dwarf spheroidal (dSph) satellites of the Local Group have long been thought to be simple spheroids of stars embedded within extended dark matter halos. Recently, however, evidence for the presence of spatially and kinematically…

Astrophysics · Physics 2009-11-11 Alan W. McConnachie , Jorge Penarrubia , Julio F. Navarro

We study the dwarf spheroidal galaxies in the nearby M81 group in order to construct their photometric metallicity distributions and to investigate the potential presence of population gradients. We select all the dwarf spheroidals with…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-26 Sophia Lianou , Eva K. Grebel , Andreas Koch

We derive ages, metallicities and [alpha/Fe] ratios from the integrated spectra of 23 globular clusters in M31, by employing multivariate fits to two stellar population models. In parallel we analyze spectra of 21 Galactic globular clusters…

The Andromeda galaxy is the best-known large galaxy besides our own Milky Way. Several images and studies exist at all wavelengths from radio to hard X-ray. Nevertheless, only a few observations are available in the microwave range where…

Pisces VII/Triangulum III (Pisc~VII) was discovered in the DESI Legacy Imaging Survey and was shown to be a Local Group dwarf galaxy with follow-up imaging from the 4-m Telescopio Nazionale Galileo. However, this imaging was unable to reach…

We present a kinematic and spectroscopic analysis of 38 red giant branch stars, in 7 fields, spanning the dwarf spheroidal galaxy Andromeda XXVII and the upper segment of the North West Stream. Both features are located in the outer halo of…

We present deep HST/ACS observations of the G1 clump, a distinct stellar overdensity lying at ~30 kpc along the south-western major axis of M31 close to the G1 globular cluster (Ferguson et al. 2002). Our well-populated colour-magnitude…

By applying a digital filtering technique to 1550 square degrees of the POSS-II in the vicinity of M31, we found two previously unidentified very low surface brightness dwarf galaxies which we designate And V and VI. Follow-up imaging with…

Astrophysics · Physics 2007-05-23 Taft E. Armandroff , James E. Davies , George H. Jacoby

This paper is the first in a series which studies interactions between M31 and its satellites, including the origin of the giant southern stream. We construct accurate yet simple analytic models for the potential of the M31 galaxy to…

Astrophysics · Physics 2009-11-10 J. J. Geehan , M. A. Fardal , A. Babul , P. Guhathakurta

Low-mass early-type galaxies, including dwarf spheroidals (dSph) and brighter dwarf ellipticals (dE), dominate the galaxy population in groups and clusters. Recently, an additional early-type population of more extended ultradiffuse…